Government Services. From distributing tax forms to taking passport photos and delivering ballots overseas, the US mail moves government services. USPS is the only delivery service that reaches every mailbox in the nation, including PO Boxâ¢ addresses and APO/FPO/DPO addresses. Passport Services.
1 Dorsal fins are found on the back of the fish. 2  There may be up to three of them. 3  The fish uses this fin for balance in the water and sudden movements. 4  Caudal fins are also known as tail fins.5  This is what we refer to as the fish's tail. 6  Anal fins are on the ventral (bottom) surface of the fish, behind the anus. Dorsal fins are found on the back of the fish. 2  There may be up to three of them. 3  The fish uses this fin for balance in the water and sudden movements. 4  Caudal fins are also known as tail fins.
In some fish, e.g., the eel, a single fin extends from the back, around the tail, and along the ventral surface. In the majority of fishes, however, there are one, two, or three dorsal fins, a distinct tail fin, and an anal fin. These are called median, or unpaired, fins.In addition to these unpaired fins, most fish also have paired fins.he tail is an important organ of locomotion and the paired fins are used for steering, checking speed, balancing, and for slow movements. An adipose fin (fatty tissue without support) is found behind the dorsal fin in some fish, e.g., the salmon and the catfish. See climbing perch; flying fish. Cite this article.